Phenolic resins have been used as components of demulsifier and dehazer formulations, e.g., in oilfield, refining, and fuel applications. These resins are useful for the efficient separation of emulsions, e.g., separating oil from water. Depending how the phenolic resins are prepared, the phenolic resin may contain mainly linear phenolic resins or a mixture of linear phenolic resins and cyclic phenolic resins (e.g., calixarenes). For instance, certain oil field resins can contain 20% or more calixarenes.
It is advantageous to use phenolic resins containing a mixture of linear phenolic resins and cyclic phenolic resins because the linear/cyclic phenolic resin mixture is a more efficient demulsifier in certain oil emulsions compared to the phenolic resin containing mainly linear phenolic resins.
However, the main problem of using the phenolic resins containing the linear/cyclic phenolic resin mixture is the instability of the product. When the phenolic resin containing such a mixture is prepared, significant amounts of insolubles will typically precipitate out of the resin solution. Thus, the final product typically settles and forms a cake at the bottom of the container when stored for a short period of time, making it difficult to be processed further. To obviate this problem, the resin material can be made and shipped hot and within a short distance. However, this solution can significantly limit the utilization of the phenolic resin product.
Therefore, there is a need in the art to develop a process to stabilize phenolic resins containing a mixture of linear and cyclic phenolic resin to improve the solubility and stability of the phenolic resins in a hydrocarbon solvent. This invention answers this need.